16 THE SCIENTIFIC FEEDING OF ANIMALS 



c. Nitrogen-Free Glycosids 



Prominent among the nitrogen- free glycosids is the poisonous principle 

 of the seeds of corncockle, githagin. Thistles and nettles contain very 

 small quantities of glucosids. The latter are the basis of the tonic effects 

 of these plants on digestion and milk secretion. Hence the custom of 

 feeding them to horses in the spring of the year. 



d. Bitter Principles 



Absinthin, derived from wormwood (Artimesia absinthium), gentiopi- 

 crin, derived from gentian root, and angelicin, derived from the carrot. 

 In small quantities they stimulate the appetite and promote the secretion 

 of gastric juice and the muscular movements of the stomach. 



B. The Conservation and Preparation of Feeding Stuffs 



I. Conservation 



The varied methods of feeding stuff conservation may be loosely 

 summed up under the following heads : 



1. Storage (in cellars or pits). 



2. Curing or drying. 



3. Fermentation. 



The nature of the feeding stuff, economic conditions, weather and cli- 

 matic conditions, determine the method of conservation. 



1. Storage 



The object of storage in cellars or in mounds of earth or pits (pitting) 

 is to protect feeding stuffs from external influences and keep them in a 

 fresh and live state. This method of conservation is adapted for root 

 crops^, potatoes, beets, carrots, turnips, etc., during the cold season only. 



Losses from storage. — The root crops are living feeding stuffs. They 

 manifest a certain amount of vital activity (respiration — take in oxygen 

 and give off carbon dioxide), and thus consume a certain amount of food. 

 This loss affects mainly the carbohydrates. Starch and cane sugar, 

 through processes of fermentation, are spHt up into grape sugar, and the 

 latter is oxidized in the act of respiration. The degree of loss, in potatoes, 

 depends on variety, temperature and moisture conditions. According to 

 Baessler, De Wet variety lost 2.5 per cent during five months' storage, 

 and the "Up to Date" variety 16.3 per cent under the same conditions. In 

 the experiments of Von Feilitzen, among 46 varieties of potatoes tested, 

 the loss ranged between 4 and 25 per cent. According to Nobbe, six 

 months' storage under damp and warm conditions resulted in a loss of 

 47 per cent, while under cool and dry conditions the loss was only 12 per 

 cent. Sugar beets when stored in a cool place suffer a daily loss of 0.01 

 to 0.02 per cent of the sugar content. In beets the loss during the whole 



3The hardy artichoke is usually left in the ground over winter and dug up and fed fresh in 

 the spring of the year. 



